Embolization microcatheter

Abstract

Microcatheter for delivering a substance (e.g., infusion agent including embolization material and / or contrast enhancing material) in a small blood vessel towards a target bodily part. Includes a single lumen surrounded by tubular wall having outer diameter and opened at both ends; tubular wall proximal portion is connectable to a pressure source and reservoir containing infusion agent, and tubular wall distal portion ends with a tip; the tubular wall distal portion includes an infusion agent flow disruption section configured to disrupt passage therethrough of incoming retrograded flow of infusion agent, during continuous delivery of infusion suspension from the reservoir to the tip. Disclosed are methods using the microcatheter for performing local embolization in a small blood vessel feeding a (for example, cancerous) target bodily part, and for delivering infusion agent in a small blood vessel towards such target bodily part. Also disclosed are devices and methods for filtering non-target infusion agent.

Description

FIELD OF THE INVENTION[0001]The present invention, in some embodiments thereof, relates to microcatheters and methods for delivering a substance (e.g., an infusion agent including embolization material and / or contrast enhancing material) to a target bodily part, for example, located within the cardiovascular system, and in particular to an embolization microcatheter, uses thereof in performing local embolization procedures, and delivering an infusion agent (for example, embolization beads with contrast enhancing material). Some embodiments of the invention are applicable for: (i) delivering an infusion agent including embolization material and / or contrast enhancing material in a small blood vessel towards a target bodily part, and (ii) performing local embolization in a small blood vessel feeding a (for example, cancerous) target bodily part, thereby forming emboli in small blood vessels, while preventing or minimizing non-target embolization (associated with contrast enhancing mate...

AI Technical Summary

Benefits of technology

[0008]According to an aspect of some embodiments of the present invention, there is provided an embolization microcatheter for delivering an infusion agent in a small blood vessel towards a target bodily part, the microcatheter comprising: a single lumen surrounded by a tubular wall having an outer diameter and opened at both ends; a proximal portion of the tubular wall is connectable to a pressure source and to a reservoir configured for containing an infusion suspension of the infusion agent in an infusion fluid, and a distal portion of the tubular wall ends with a tip; the tubular wall distal portion comprises an infusion agent flow disruption section applicable via the lumen and configured, when applied, to disrupt passage of an incoming retrograded flow of the infusion agent around periphery of the tubular wall distal portion adjacent thereto, during a continuous delivery of the infusion suspension from the reservoir to the tip. The use of a microcatheter having a single lumen only, for delivering the infusion suspension together with disrupting retrograded flow, optionally selectively or in reaction to change is surroundings (e.g., elevation of ambient pressure above a certain degree), is advantageous, for example, for keeping the microcatheter structure as small as possible, therefore having it fit for passage through a larger-sized catheter or / and into small blood vessels.

[0009]According to some embodiments of the invention, the flow disruption section is configured to diminish velocity of the incoming retrograded flow of the infusion agent, to divert or block the incoming retrograded flow of the infusion agent, to cause turbulence or vortex in the incoming retrograded flow of the infusion agent, or / and to increase local pressure thereabout.

[0025]According to some embodiments of the invention, the flow disruption section comprises material being permeable to the infusion fluid and impermeable to the infusion agent, such that when the flow disruption section stretches to the second average diameter, the impermeable material allows flowing of the infusion fluid therethrough and prevents passage and flowing of the infusion agent therethrough.

[0027]According to an aspect of some embodiments of the present invention, there is provided a method for performing local embolization in a small blood vessel feeding a cancerous target bodily part, the method comprising: providing an embolization microcatheter comprising a tubular wall having an outer diameter, enclosing a single lumen extending therealong, and including a distal portion ending with a tip opened to the lumen with a distal outlet, the tubular wall distal portion comprises an infusion agent flow disruption section applicable via the lumen and configured to disrupt passage around periphery of the distal portion of an incoming retrograded flow of infusion agent, during a continuous delivery of an infusion suspension of the infusion agent in an infusion fluid through the lumen to the tip; locating the target bodily part and the small blood vessel using an imaging technique; providing a catheter in close proximity to a proximal entry to the small blood vessel or to an interim blood vessel opened to the small blood vessel downstream thereto, the catheter comprises a hollow passage opened to the small blood vessel and has an inner diameter equal to or less than about 1 mm; passing the microcatheter through the hollow passage and into the small blood vessel, whereby the small blood vessel reaches a first average ambient pressure upon the tubular wall placement therein; delivering the infusion suspension through the lumen and the distal outlet to the target bodily part; accumulating the infusion suspension between the microcatheter tip and the target bodily part, characterized by an increase of pressure within the small blood vessel to a second average ambient pressure; and allowing or / and applying the infusion agent flow disruption section to disrupt an incoming retrograded flow of the infusion agent passing therethrough during the continuous delivery of the infusion suspension through the lumen to the tip, by diminishing, blocking or / and causing turbulence in the incoming retrograded flow of the infusion agent.

[0030]According to some embodiments of the invention, in the method, the pressurizing actuates the flow disruption section to diminish, block, or / and cause turbulence in, the incoming retrograded flow of the infusion agent, thereby increasing local pressure thereabout. According to some embodiments of the invention, in the method, the pressurizing is performed until the infusion agent occludes the small blood vessel or / and until a selected pressure difference is developed between the tubular wall distal portion and the target bodily part.

[0033]According to an aspect of some embodiments of the present invention, there is provided a method for performing local embolization in a small blood vessel feeding a cancerous target bodily part, the method comprising: providing an embolization microcatheter comprising a tubular wall having an outer diameter, enclosing a single lumen extending therealong, and comprising a distal portion ending with a tip opened to the lumen with a distal outlet, the tubular wall distal portion comprises an infusion agent flow disruption section applicable via the lumen and configured to disrupt passage therethrough of an incoming retrograded flow of an infusion agent, during continuous delivery of an infusion suspension of the infusion agent in an infusion fluid through the lumen to the tip; passing the microcatheter into the small blood vessel until the tip of the microcatheter is located at a chosen distance from the target bodily part; delivering the infusion suspension via the distal outlet towards the target bodily part; allowing or / and applying the infusion agent flow disruption section to disrupt an incoming retrograded flow of the infusion agent passing therethrough during the continuous delivery of the infusion suspension through the lumen to the tip, by diminishing, blocking or / and causing turbulence in the incoming retrograded flow of the infusion agent; selecting a blood vessel portion upstream to the small blood vessel, and monitoring the blood vessel portion using an imaging technique; via the monitoring, detecting an indication of presence of the infusion fluid in the blood vessel portion; and in response to the detected indication, stopping the delivery of the infusion suspension.

Problems solved by technology

One of the problems associated with embolization is commonly known as “non-target embolization”, where the embolic material travels to small blood vessels other than to those which directly feed the target tumor or region.

This can damage healthy tissues in these areas, often resulting in serious complications.

Possible scenarios include gastric ulcers with liver embolization, as well as cases where embolic material refluxes alongside the microcatheter reaching the wall of the stomach, possibly causing ischemia and ulceration.

These vessels cannot be accessed with a larger and often stiffer catheter.

Also, blood vessels in the body tend to go into spasm when manipulated, causing an ineffective embolic material delivery, so flexible micro-sized catheters are preferred to avoid such scenarios.

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